1. Field of Invention
The present invention relates to an executive device, a stack method and a stack system thereof. More particularly, the present invention relates to an executive device for identifying a stack status and executing an instruction, as well as a stack method and a stack system thereof.
2. Description of Related Art
Currently, an executive device having a micro-controller or a system on chip is usually connected to a host such as a personal computer (PC) for operation via a connection interface such as a USB (Universal Serial Bus) or a RS-232 (Recommended Standard number 232).
However, the conventional RS-232 interface cannot realize the stack connection between multiple executive devices, i.e. the serial connection between several executive devices. The USB protocol is highly complex, and a compatible driver is required to be additionally developed on the host side, which is time-consuming and requires the host to be equipped with quite many USB connection ports in order to connect multiple executive devices at the same time.